Carburetor



NOV. 10, 1936. J A SPEED 2,060,538'

CARBURETOR Filed June 28, 1935 2 Sheets-Sheet l N0v.1o,193'6. M. SPEED y "2,060,538

` CARBURETOR l Filed June 28, l1955 2 sheets-sneet 2 juz.

Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a carburetor and more particularly pertains to carburetors of the type employed in connection with internal cornlloustion engines in the production of an explosive mixture of a hydrocarbon fuel and air.

An object of the invention is to provide a carburetor in which progressively increased volumes of the fuel mixture will be supplied the engine as the speed and fuel demanded of the engine increases, and conversely the volume of fuel supply progressively diminished as the engine speed and demand decreases, and in which such progressive increase vand reduction of fuel supply is effected by the action of the flow of the fuel at varying velocities past tiltable vanes controlling valves for regulating the feed of the fuel to the engine.

Another object is to provide an arrangement in the automatic fuel supply control whereby .great turbulence of the fuel and air during flow thereof into a mixing chamber will be effected, and whereby a rapid and thorough intermixture 0f the fuel and air will be insured. l

Another object is to provide a construction whereby the controlling vanes may be adjusted as `occasion may require to vary the moment of their action either in cutting in or cutting out a fuel feed jet controlled thereby, so that the several Vanes may be caused to act at any predetermined point of engine speed as may beV desired and whereby the progressive operation of the several vanes may be either at relatively uniform or Variable intervals.

`A further object is to provide a construction in a carburetor of the above character which is simple and adapted to be readily applied and which is not likely to get out of order during operation.

.Various additional objects and features of the invention will appear and will be more fully understood from the following detailed description ,of a present preferred embodiment thereof, ref'- erence for this purpose being had to the `accompanying drawings, in which;

Fig. 1 is a"view of the carburetor in vertical section with parts shown in elevation, as seen on the line I-I of Fig. 2;

Fig. 2 is a detail in horizontal section and plan taken on the line 2-2 of Fig. 1;

Fig. 3 is a detail in vertical section as seen on the line 3-3 of Fig. 1 with parts inelevation;

Fig. 4 is a perspective viewY of one of the controlA vanes and an associated valve as removed;

Fig. 5 vis a horizontal section and plan view taken `on the line5-5 of Fig. 1;

Fig. 6 is a detail in vertical section and elevation as seen on the line 6 6 of Fig. 1 in the direction indicated by the arrows;

Fig. 7 is a view in Vertical section and elevation as seen on the line 'l-'l of Fig. 1 in the direction indicated by the arrows;

Fig. 8 is a View of the carburetor as seen in side elevation; showing it as disposed in a down draft position;

Figs. 9, 10 and 11 are schematic views in side elevation illustrating the Inode of operation of the invention;

Referring to the drawings more specifically A indicates generally a carburetor which embodies a fuel reservoir B to which liquid fuel is supplied through a strainer C under control of a float D in a fashion common in carburetor construction; the fuel being delivered to the strainer C through a conduit I2 leading from any suitable source of fuel supply.

Arranged adjacent the reservoir B is a pair of spaced chambers E and F separated by a wall I3 which chambers constitute respectively an air chamber and a mixing chamber. The wall I3 is formed with a plurality of Venturi shaped openings, here shown as four in number and indicated respectively at a, b, c and d and associated with the openings a, b, c and d is a series of fuel feed nozzles e, f, g and h, there being at least one of such nozzles arranged to eject fuel into the mixing chamber F from each of said openings. The nozles e, f, aand h are formed on conduits i. j, lc .and l respectively, which conduits lead through the wall I3 andcommunicate with the fuel reservoir through feeders m, n, o and p. Each of the feeders embodies a tubular stem I4 arranged in a well I 5 formed in a side wall of the reservoir B and rhaving a .fuel inlet opening I6 in the lower end thereof with which the lower end of the tube I4 is engaged as particularly shown in Fig. 1; the tube I4 being formed with a threaded upper en d portion as indicated at I'I screwed into vcompanion threads -on the wall of the Well. The lower end portions of the tubes I4 are formed with a series of openings I8 communicating with the well and the upper portions of the tubes are formed with annular channels I9 with which the inner ends of the conduits i, y', lc and Z communicate; the channels being formed in the threaded portions I1, intermediate the ends of the latteri whereby the channels are separated from the .wells I5, Openings 20 are formed in the stems and lead from the channels I9 to the interiors of the stems.

The lower endof the air chamber E is formed with an inclined bottom wall 2| formed with an air inlet opening 22 which opening is adapted to be closed by a leaf choke valve 23 carried on a rock shaft 24 which shaft is engaged by a coil spring 25 arranged in a turnable housing 26 to which the other end of the spring is aflixed. The spring 25 is tensioned to hold the valve 23 in an open position.

Affixed to the housing 2B is a sleeve 2'I carrying an arm 28 adapted to be rocked to effect turning of the housing 26 and thereby act through the spring 25 to turn the shaft 24 to swing the valve 23 to its closed position, or to a partly closed position, to effect a choking action in a fashion common in carburetor construction.

The mixing chamber F is formed at its upper end with an outlet tube 29 adapted to be connected to the intake manifold of an internal cornbustion engine and which tube is fitted with the usual throttle valve 30, and leading into the tube 29 is a passage 3l fitted with a needle valve 32 which passages communicate with a passage 33 leading to the fuel reservoir B. The passages 3| and 33 constitute a usual form of idling jet.

The essence of the present invention resides in interposing between the Venturi openings a, b, c and d and the mixing chamber F a series of separated and independent passages q, r, s and t each of which is rectangular in cross section and has inside dimensions approximate the diameter of the enlarged end of the Venturi opening.

Arranged in each of the passages r, s, and t is a throttle valve 35 carried on a rock shaft 36 extending through and journalled in one side wall of the passage and carrying on its outer end a sleeve 3'I to which is connected one end of a coil spring 38, having its other end affixed to a collar 38', as particularly shown in Fig. 6. Formed on the sleeve 3`I is a vane 39 which extends in lateral relation to the axis of the rock shaft 36 and projects over the outer end of an adjacent passage; the vane 39 connecting with the rock shaft of the valve in the passage r leading over the outer end of the passage q; the vane 39 on the shaft of the valve in the passage s extending over the outer end of the passage r and the Vane 39 on the shaft 36 of the valve in the passage t extending over the outer end of the passage s.

It is to be noted that the passage q is valveless and aside from the vane 39 projecting thereover affords a normally open communication between the air chamber E and the mixing chamber F, While the remaining passages r, s, and t are normally closed by the valve 35 under the action of the springs 38.

The vanes 39 are of a length to extend completely over the outer ends of the passages and are of Widths slightly less than the widths of the passages so as to aord a space between one edge of the vane and the adjacent margin of a passage for the flow of fuel mixture past one edge of the vane. i

As a means for enabling varying the extent of the opening between the margin of the vane and the adjacent margin of the passage the vane is equipped with a plate 49 which seats on the upper face of the vane and is adjustably connected thereto by a screw extending through a transversely elongated slot 42 in the plate and screwed into engagement with the vane 39. The plate 40 is thus adapted to be adjusted laterally on the vane 39 to project over the space between one edge of the vane and the adjacent edge of the passage.

The passages q, 1', s and t are formed in a unit of cast metal which is held in place on the wall I3 by means of pins 42 carried by the Wall I3 and extending through openings in lugs 43 formed on the walls of the passage unit; the pins serving to hold the unit against lateral shifting relative to the wall I3. Extending over the central portion of the unit and seating thereon is a tapered cap 44 which is engaged by a bolt 45 which extends therethrough and is screwed into engagement with the central portion of the plate I3 whereby the unit is clamped on the wall.

In the schematic arrangement shown in Figs. 9, 10 and 11 passages q, r, s and t are illustrated as arranged in a line, with the valves 35 connected to operating vanes 39 through the medium of links u connecting with cranks 'u and w carried by the valves and vanes respectively, whereby rocking movement of either of the vanes 39 will effect corresponding movement of its associated valve 35 in a fashion similar to that obtained by the construction previously described.

In the application and operation of the invention the valves 35 are normally maintained closed under the urge of the springs 38, and on negative pressure being developed in the mixing chamber F, opening the throttle valve 3D as is occasioned by operation of an engine to which the carburetor is applied in the manner well known in the art, a flow of air will be induced through the opening 22, chamber E, then through the opening a and past the vane 39 extending over the latter.

The flow of air through the Venturi opening a around the nozzle b will act by reason of its velocity to induct fuel from the nozzle e and thereby effect a mixture of vaporized fuel and air in the pasasge q, which mixture passes into the mixing chamber F and past the then open throttle Valve 39 to the engine. On increase of engine speed or engine demand the velocity of flow of air through the Venturi opening a and passage q increases and may increase to such extent as to effect lifting of the vane 39 extending over the passage q in opposition to the spring 38 and thereby cause opening of valve 35 in the passage r whereupon a volume of air will pass through the Venturi opening b around the nozzle f and past the vane 39 extending over the passage 1* thereby effecting delivery of fuel from the nozzle f and forming an increased volume of fuel and air mixture which will pass from the passage r into the mixing chamber F.

In like fashion increased velocity of the uid mixture through the passage 1' will act on the vane 39 extending thereover so as to open the valve 35 in the pasasge s to permit the ow of air through the Venturi opening c and the consequent induction of fuel from the nozzle y to direct an increased volume of the fuel and air mixture into the mixing chamber F past the vane 39 extending over the passage s. In like manner a predetermined increase of the velocity of the ow of the fluid mixture through the passage s will act on the Vane 39 extending thereover to open the valve 35 in the passage t thereby causing the flow of air through the Venturi opening d past the nozzle h to induce the flow of fuel from the latter and form a still further increased volume of the fuel and air mixture which will flow from the passage t into the mixing chamber F.

The volume of fuel and air mixture delivered from the several passages q, r, s and t will become ntermixed in the chamber F by reason of turbulence of the mixture set up in the latter. By forming the passages q, r, s and t of rectangular cross section considerable turbulence is set up therein on the ow of air and fuel from the circular Venturi openings a, b, c and d, which serves to thoroughly intermix the air and fuel vapors as they pass or flow through the passages and which mixture is further enhanced by the flow of the initial mixture around the vanes 39 which will then act as bailles.

The nozzles e, f, g and h are arranged in such fashion as to effect vaporization of the fuel ejected therefrom, being so disposed as to be normally substantially lled with fuel under gravity flow of the latter from the reservoir B.

It will be seen that variations in negative pressure created by varying speed and demand of the engine to which the mixing chamber F is connected, will effect varying velocities in the ilow of air through the several Venturi openings with a consequent variation in the operation of the several vanes and their associated valves, thus varying the quantity of fuel supplied to the engine according to the needs of the latter.

By adjusting the width of the vanes 39 by shifting the plate 40 laterally thereon, the moment of lifting of the vanes and consequent opening of its associated valve may be varied as occasion may require.

The manner in which several vanes and their associated valves are successively operated is graphically illustrated in Figs. 9, 10 and l1, in which Fig. 9 shows in full lines the several vanes disposed in their normal closed position, and indicated in dotted lines the operation of the first vane and its associated Valve, while in Fig. 10 the rst vane and valve are shown in their fully open position with the second vane partly open, and in Fig. l1 all the vanes and valves are shown as in their fully open positions.

While I have shown the several Venturi openings, passages and nozzles of corresponding formation, it will be manifest that each of such elements may be varied in its dimensions relative to the other so as to obtain a wide range of Variable action, and also facilitate designing of the carburetor to meet varying conditions.

The carburetor as here shown is equally applicable for use either as an up or a down draft carburetor.

I claim:

1. In a carburetor, a fuel and air mixing chamber, a plurality of jets for directing fuel toward said chamber, means for supplying fuel to said jets, means for directing air to said chamber past said jets including a plurality of separated passages interposed between said jets and said chamber, there being at least one of said jets opening to each of said passages, one of said passages being normally open, valves normally closing each of the other passages, means controlled by the flow of fuel and air through said open passage controlling the Valve in another of the passages, and means controlled by the oW of fuel and air past the opened valve for effecting opening of a valve in still another of the passages.

2. In a carburetor, an air chamber, a mixing chamber, a wall interposed between said chambers having a series of Venturi openings therein, a series of separated passages leading from said openings to said mixing chamber, a fuel nozzle opening to each of said passages, means for supplying fuel to said nozzles, valves normally closing certain of said passages, and means controlled by the flow of fuel and air through certain of said passages controlling the opening and closing of valves in other of said passages.

3. In a carburetor, an air chamber, a mixing chamber, a wall interposed between said chambers having a series of Venturi openings therein, a series of separated passages leading from said openings to said mixing chamber, said passages being of rectangular cross section, a fuel nozzle opening to each of said passages, means for supplying fuel to said nozzles, valves normally closing certain of said passages, and means controlled by the flow of fuel and air through certain of said passages controlling the opening and closing of valves in other of said passages.

4. In a carburetor, a wall formed with a series of circular openings, a unit adjacent said Wall formed with a series of passages, said passages leading from said openings, means for delivering fuel to each of said passages through said openings, one of said passages being normally open, valves normally closing the other of said passages, means controlled by the flow of air through said normally open passage for opening the valve in another passage, and means controlled by the llow of air through the opened valved passage for eifecting opening of a valve in another passage.

JAMES A. SPEED. 

